Radiator



J. MCELGIN Nov. 29, 1938.

Two-dog, SELG/N,

W w yw `TOHN M Patented Nov. 29,, 1938 UNITED STATES PATENT OFFICE 2,138,17 aADIA'roa John McElgln, Philadelphia, Pa., assignor to John J. Nesbitt, Inc., Holmesburg, Philadelphia, Pa., a corporation of Bennsylvania Application June 16, 1937, Serial No. 148,533

8 Claims.

the like such as are employed -in unit ventilators,

unit heaters, central fan heating and air conditioning systems.

It is a further object of this invention to provide, in radiator means, return flow steam 'distributing tubes for use in condensing tubes of heating elements having extended surfaces.

It-is a further object of this invention to provide, in a methodrof steam distribution, for 'directing through a closed channel excess steam from the retum end` of such a condensing tube to the steam end thereof.-

It is a fm'ther object of this invention to 'provide a return flow steam distributing tube structure particularly adapted to provide uniformity of steam distribution to a radiator condensing tube irrespective of the capacity orV supply o'f heating steam thereto.

It is a further object of this invention to provide such structure wherein the condensing capacity of the tube is substantially increased by the use of the return flow steam distributing tube therein.

It is afurther object of this invention'to provide such a return fiow steam distributing tube structure, by means of which,l unformity of steam distribution throughout the length of an equipped condensing tube may be achieved irrespective of the pressure and/or Velocity of steam supplied through the distribution tube.

These and -other objects and advantagesrfwill appear from the following description taken in connection with the drawings.

In the drawings: Figure-l is an elevational view, partly in section, of'a radiator having the condensing tubes thereof equippedwith returnv flow steam distributin'g tubes constructed'according to the principles of this invention;

Figure 2 is a fragmentary section taken on the line 2-2 of Figure l;

Figure 3 is a view, in perspective, partly broken away, of a radiator structure equipped according to the .principles `of this invention;

Figure 4 is a diagrammatic view, in section, showing a condensing tube of a radiator equipped with one form of return fiow steam distributing this invention and Figure 5 is a view similar to Figure 4, but showing a modified form of return flow steam distributing tube;

Referring to the drawings in detail, the radiator illustrated in Figures 1 to 5 inclusive comlprises a. steam header designated I provided with a steam inlet 2, a return header 3 provided with a steam outlet 4 and condensing tubes 5 disposed therebetween, each connected at one end to the steam header l and at the other end to the return header 3. Common fins 6 are rigidly secured in any suitable manner, in spaced relation, to the condensing tubes 5 of the radiator.

In the construction shown in Figures 1 and 3, the condensing tubes have their ends secured to the respective headers by beading over; while, as an alternative construction as shown in Figures 4 and 5, the steam or inlet header I is provided. with suitably located ,integral nipples l, each having associated therewith a threaded flange nut 8, by means of which one flanged end of a tube 5 is secured to a nipple 1. Similar nipples 9 are formed integrally with the return header 3" and are each provided with a screw-threaded flange nut Ill similar to the fiange nut 8, by

means of which the opposite fianged end of the tube 5 is secured to the return header 3.

Secured in the condenser tube 5, adjacent the inlet header, is a distributing tube support plate l provided with a suitable aperture |2, by means of which the steam distributing tube is rigidly secured in supported relation to the support plate I in such manner -as to.be disposed centrally of the tube 5 and 'in spaced relation to the inner Wall thereof. As shown in Figs. 1, 2, 3 and 4, the distributing tubes are each formed of a main tube member |3 of sami-circular or half round section having one end beaded or upset at I 3a to rigidly vsecure the tube member |3 to the support' plate H. Disposed adjacent the main tubemember |3 is a second tube member H of similar section, which tube'members together form a double conduit of circular or round exterior section' The ends of the tube members 13 and 'll are closed by the cap or cap member .|5 which. is rigidly secured to the end portions of the tube members' A|3 'and |4 in any suitable manner. The tube members IJ and |4 are thus secured to form,,with

the cap or cap member lIS, avU-shaped return' flow conduit for steam entering .from the inlet end of the tube member 3 and flowing from the outlet end |6 of the tube member ll.

The tubel member v|3 is provided, along its length, withia plurality of apertures ll, through which steam flowing through the tube member i3 may escape to the space between the exterior of the distributing tube and the interior of the condensing tube 5. Similar apertures |8 are provided along the length of the tube member Ill.

In the embodiment illustrated in Figure 5, the steam distributing tube comprises a U-shaped tube member |9 upset or beaded over at one end 20 to rigidly secure the tube member |9 in supported relation to the support plate II. The opposite or outlet end 2| of the tube member |9 is directed toward the support plate Ii and is disposed adjacent thereto. Throughout its length the tube member |9 is provided with apertures 22 which are unequally spaced in the same manner as are the apertures i'l in tube member |3 and apertures |8 in tube member |4, as shown in Fig. 5, and which apertures are likewise of different areas.

Heretofore, in the construction of blast steam heating surfaces, the primary aim has been the achievement of a high condensing capacity in a compact space. While certain existing fin and tube constructions have successfully met this requirement, scant attention has been paid, however, to the performance (and efflciency) of the surface under less than maximum demand. The efliciencyof operation at less than maximum capacity has become an extremely important consideration since the application of automatic control to heating, ventilating and air conditioning systems. Is is, therefore, necessary, in the construction of heating surfa-ces, to consider the flexibility or ability of a surface efllciently to 'adapt itself to v'close and continuous control'as .well as its ability to transfer heat. The use o f multiple distribution tubes. in dividing each condensing tube or element into multiple lengths whichV are separately fed from the main header, has substantially improved thisconditlon. However, even by the use of multiple tubes, either concentrically arranged or otherwise, it is necessary to accept along, this channelway, provide for the flow of steam entering the channel into the space between the distributing channelway and 'the interior of the condensing tube 5. Any excess steam or steam not fiowing through apertures. l'l and |8 must flow from the outlet .end IS of the channelway, which is adjacent the steam end of the condensing tube-li. 'The direction of flow of excess steam to the steam end of the condensing tube 5 instead of the return end thereof prevents starving of the steam end of the condensing tube 5, where the steam capacity or Velocity .of steam flow through the distributing tube is substantial or of such magnitude as hitherto caused the failure of flow through the orifices in straight distributing tube lengths.

By the use of the return channelway or U-shaped path provided by the return flow distributing tubes of Figures 4 and 5, all parts of the condensing tubes 5 receive a full quantity of steam when full steam pressure is supplied. A wide control of distribution may be exerted, while substantially no loss of capacity (as compared with condensing tubes unequipped with distributing tubes) is sustained.

While the use of multiple distribution tubes, either concentrically arranged or otherwise, and provided with orifices predeterminedly spaced along their lengths and having a greater number of orifices or a greater orifice area at the return end of the distributing tube, has been quite satisfactory in operation at reduced steam capacity; when the valve is wide open and the heat element Operating at its full capacity, the steam tends to rush through the tube to the retum end of the element whereby higher capacity is obtained at the return end than at the steam end of the element and uniformity of distribution is destroyed. This causes a reduction of condensing capacity at the steam end of the element and the respective condensing tubes thereof. The high Velocity of steam in the various orifices of these straight or multiple distributing tubes prevents the flow of excess steam from the return end backwardly in the condensing tube to the steam end. The desired distribution is, therefore, obtained at the expense of ultimate capacity due to the fact that the efiiciency of the heating element at high capacity is substantially reduced by the use of such tubes, wherein the excess steam is conducted from the steam or inlet header through a straight path and delivered from an outlet situated at the return end of the condensing tube.

By conducting the excess steam through a substantially U-shaped or retum path, and delivering it at the inlet or steam end'of the condensing tube, I, therefore, totally obviate the loss of efliciency at high capacity and provide structure for and a method of steam distribution, whereby 'the ultimate heat energy is extracted from the steam which is prevented from passing through the condensing tube of the heating element with such rapidity as to prevent the extraction therefrom of the ultimate degree of heat energy.

While the operation of the structure shown in Figures 1 to 4 inclusive has been described, it is.

of course, to be understood that the prinoiple of operation of the structure shown'in Figure 5 is substantially identical therewith. In the operation of the structure shown in Figure 5, steam from the inlet or steam header i passes through the inlet end of the tube member 19 and a portion thereof escapes through the suitably spaced orifices 22, while any steam not escaping therethrough, which may be termed excess steam", is conducted through a return or substantially U-shaped path from the inlet end of the tube I!! to the Outlet 2| thereof, which outlet opening is directed toward and disposed adjacent the distributing tube support plate I, at the steam end of the distributing tube 5. v

Where'the diameter of the tube 5 is such as to permit the use therein of the construction of the distributing tube illustrated in Figure 5, the use of this tube may, in some cases, be preferable, but where the condensing tube diameter is substantially small and it is necessary to provide a compact return flow distributing tube structure, it is, of course, desirable to utilize the construction shown in Figure 4. The performance and essential features of each construction of tube are substantially the same,

The size, location and/or spacing of the apertures |1, |8 and 22 are preferably (but not necessarily) non-uniform and susceptible of substantial Variation inadapting the structure to various ranges and conditions of operation.

It is, of course, to be understood that the above desoribed structure is merely illustrative of the manner in which the principles of my invention may be utilized and that I desire to comprehend within my invention such modifications as come within the scope of the claims and the invention.

Having thus fully described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a radiator, spaced headers, an Interconnecting condensing tube, and a distributingtube on the interior of said condensing tube defining a return path extending from a point adjacent one header through a bend adjacent the other header and thence to a point adjacent said first header.

2. In a radiator, spaced headers, an Interconnecting condensing tube, and a distributing tube on the interior of said condensing tube defining a retum path extending from a point adjacent one header through a bend adjacent the other header and thence to a point adjacent said first header, said tube having predeterminedly spaced apertures throughout the length thereof.

3. In a radiator, spaced inlet an d outlet headers, an interconnecting main tube between said headers, and means on the interior of said tube defining a return path having an inlet communicating with the inlet header and an outlet adjacent said inlet header, said path extending from a point adjacent said inlet header to a point adjacent said outlet header and returning to a point adjacent said inlet header.

4. In a radiator, spaced headers, an Interconnecting main tube, and means on the interior of said tube defining a return path having an inlet communicating with one header and an outlet adjacentrsaid header, said path extending from apoint adjacent said header through a bend adjacent said other header and containing predeterminedly spaced outlets throughout the length thereof.

5. In a radiator, spaced headers, an interconnecting main tube, and means on the interior of said tube defining a retum path having an inlet communicating with one header, an outlet adjacent said header, said path extending from a point adjacent said header through a bend adjacent said other header and containing predeterminedly spaced outlets of predetermined size throughout the length thereof.

6. In a heater exohanger, an inlet header, a return header spaced therefrom, a heat exchange tube connected between said inlet header and said return header, an apertured distributing tube support plate in said condensing tube adjacent the inlet header, a fiuid distributing tube having one end secured in said aperture and communicating with said inlet header and having an outlet adjacent its other end, said distributing tube having therein a bend adjacent said return header, and its other end adjacent and directed toward said distributing tube support plate, said tube support plate adjacent said aperture having a solid baflle portion which serves to repel and re-' direct the fluid issuing from said outlet in said other end of said tube.

7. In a heat exchanger, an inlet header, a return header, a heat exchange tube connected therebetween, and steam distributing means in said heat exchange .tube comprising a pair of' pipes of semi-circuiar section with fiattened side wall portions, a cap connecting adjacent ends of said pipes and supporting said flattened side wall portions substantially in engagement, the opposite end of one pipe having communication with said inlet header, and the opposite end of the other pipe having communication with the interior of said heat exchange tube at the end thereof adjacent said inlet header.

8. In a.heat exchanger, an inlet header, -a return header, a heat exchange tube connected therebetween, and steam distributing means in said heat exchange tube comprising a pair of pipes of semi-circular section with fiattened side wall portions, a cap connecting adjacent ends of said pipes and supporting said fiattened side wall portions substantially in engagement. the opposite end of one pipe having communication with said inlet header, and the opposite end of other pipe having communication with the interior of said heat exchange tube at the end thereof adjacent said inlet header, said pipes having predeterminedly spaced apertures therein providing communication between the interior of the path defined by said tubes. and the interior of said heat exchange tube.

JOHN McELGIN. 

